Reservoir empty indicator



Sept. 13, 1966 N. L. KENDT ETAL RESERVOIR EMPTY INDICATOR 5 Sheets-Sheet l Filed April 23, 1964 INVENTORS Tm WN Y EE E KK N LD T .fC MA m m E mm H @Y B Sept. 13, 1966 N. 1 KENDT ETAL 3,272,01

RESERVOIR EMPTY INDICATOR Filed April 23, 1964 5 Sheets-.Sheet 2 INVENTORS 44 58 NORMAN L. KEMDT THEIR ATTOR MEV Sept. 13, 1966 N. L. KENDT ETAL 3,272,011

RESERVOIR EMPTY INDICATOR Filed April 23, 1964 l 5 Sheets-Sheet 5 F'IGLS INVENTORS NORMAN KENDT HER ATTORNEY United States Patent O 3,272,011 RESERVIR EMPTY INDICATOR Norman L. Kendt and .Iolm A. Dicken, Jr., Louisville,

Ky., assignors to General Electric Company, a corporation of New York Fiied Apr. 23, 1964, Ser. No. 361,989 7 Claims. (Cl. 73-299) This invention relates generally to an indicator means and, more specifically, to a means to indicate when a liquid reservoir has become empty.

Although the present invention may have broader application, it is particularly adapted for use in an automatic washing machine such as, for example, an automatic dishwasher. It has become quite common to provide an automatic washing machine with a treating agent dispensing means to automatically dispense a treating agent at a predetermined time, or times, during a wash cycle. An example of such a treatingy agent dispensing means would be a rinse aid injector in an automatic dishwasher. The rinse aid is injected automatically during the initial portion of the nal rinse step of the wash cycle. The rinse aid is actually a wetting agent which causes the rinse water to contact the dishes in a sheet fashion rather than a droplet fashion. This sheeting action minimizes spotting of the dishes, upon drying, because it minimizes the formation of spot-inducing droplets. The rinse aid injector usually includes a reservoir capable of storing enough rinse aid fluid for several dishwasher cycles of operation to thereby obviate relling of the injector after each cycle. Because the injector, including the reservoir, is usually positioned within the dishwasher cabinet structure for appearance reasons, it is diiiicult for the operator to observe when the reservoir empties. Therefore, it would be desirable to provide means, visible to the exterior of the cabinet, to indicate when the reservoir has become empty.

Conventional liquid level indicators such as, for example, a common sight glass, may be inappropriate for use with a dishwasher for several reasons. One reason is that the color of the rinse aid liquid may vary among the commercially available brands. In order to maintain a reasonably consistent color at the indicator irrespective of color variations of the liquid within the reservoir, it would be desirable to provide a separate indicator fluid having suitable physical characteristics with regard to color, viscosity, vapor pressure and the like.

It is often necessary to tip an automatic washing machine onto its side when servicing the machine. It would therefore be desirab-le that any indicator means be capable of experiencing a 90 movement from a vertical orientation to a horizontal orientation without affecting its operation upon return to the vertical orientation and without leakage in either position.

Accordingly, it is an object of this invention to provide an improved empty indicator for a liquid reservoir.

yIt is also an object of this invention to provide an improved empty indicator for a liquid reservoir wherein the color of the indicator is independent of the color of the liquid in the reservoir.

It is a further object of this invention to provide an empty indicator which is capable of being tipped 90 in any direction without aecting its operation once it is returned to its original position.

Briey stated in accordance with one aspect of the invention, there is provided an indicator for a liquid reservoir including a gauge having a irst end and a second end. A first tube extends from the lower portion of the reservoir to the first end of the gauge and a second tube extends upwardly from the second end of the gauge and is opened to the atmosphere. The rst tube and the second tube are each formed in a helix with the helix Patented Sept. 1?, 1966 having a major diameter substantially larger than the inside diameter of either of the tubes. Indicator fluid is normally positioned in the iirst tube when the reservoir is substantially empty and the fluid is moved into the gauge by pressure created within the irst tube when the reservoir is lled with liquid.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a side view, partially cut away to show details, of an automatic washing machine employing the present invention;

FIGURE 2 is an enlarged View of the treating agent dispenser, including the present invention, of the automatic washing machine in FIGURE 1;

FIGURE 3 is a right hand view of the device shown in FIGURE 2;

FIGURE 4 is a view taken from the right hand side of FIGURE 3;

FIGURE 5 is a View taken from the top of FIGURE 4;

FIGURE 6 is a schematic representation of the indicator of the present invention;

FIGURE 7 is an enlarged view taken along line 7-7 of FIGURE 3;

FIGURE 8 is an enlarged view taken along line 8-8 of FIGURE 2; and

FIGURE 9 is a perspective view of the present invention with some parts omitted for clarity.

Referring to the drawings and particularly to FIG- URE 1, there is illustrated an automatic washing machine in the form of a portable dishwasher 10 having an outer cabinet 11 which, in cooperation with a bottom wall 12 and a topwall 13, forms a wash chamber 14. Disposed within wash chamber 14 are dish supporting racks 15 and 16. Dish supporting rack 16 is divided into two sections, a stationary rear section 17 and a movable front section 18.

A closure member 19, of which top wall 13 forms the inner surface, is provided to allow access to wash chamber 14. Closure member 19 pivots about a hinge member 20 when opened or closed. Bracket 21 interconnects front section 18 of rack 16 with closure member 19 such that, when closure member 19 is opened, section 18 moves upwardly and rearwardly to overlie section 17. An arm 22, hingedly connected to section 18 at point 23 and also hingedly connected to cabinet 11 at point 24, is provided to control tipping of section 18 as section 18 is moved. The rack 16, and its association with closure member 19, does not form a material part of the present invention and may be substantially as described and claimed in U.S. Patent No. 3,087,769, issued to Lauren W. Guth on Apr. 30, 1963, and assigned to the General Electric Company, assignee of the present invention.

Bottom wall 12 has a centrally depressed portion forming a sump 25 so that any liquid within chamber 14 will collect therein. Supported by bottom wall 12 and sump 25 is a motor-pump unit 26. Motor-pump unit 26 includes an electric drive motor 27 and a pump 28. Pump 28 has an inlet 29 which draws liuids from sump 25 and, in one direction of rotation of motor 27, pumps this fluid up through spray arm 30l and spray tube 31. In the same direction of rotation of motor 2.7, pump 28 also pumps liquid through conduit 32, which interconnects with conduit 33 at coupling 34. T-he uid pumped into conduit 32 is ejected from spray device 35, rotatably secured to closure member 19.

VIn the opposite direction of rota-tion of drive motor 27, pump 28 draws W-ash fluids from sump 2-5 and propels them through effluent discharge outlet 36 which communicates with a normal household sewer syste-m (not shown). An electrical resistance heating element 317 may be provided in wash chamber 14 for the purpose of heating the wash fluids therein or facilitating the drying of dishware supported by racks 15 and 16 upon completion of the washing and rinsing thereof.

All of the structure thus far described is, in most respects, conventional an-d may therefore vary a great deal without materially affecting the present invention. The present invention is, as mentioned earlier, not limited in utility to application in a dishwasher, a dishwasher being shown and described for purposes of illustration only.

Attached to the fron-t side o-f cabinet 11 is a member 38 which, due to its spaced relationship with the front side of cabinet 11, forms an enclosure 39 which may house such elements as a treating agent dispensing means 4t).

Referring now to FIGURE 2, the treating agent dispensing means 40' is shown enlarged somewhat to provide greater detail and it can be seen that treating agent dispensing means 40' includes a reservoir 41 capable of containing enough treating agent for several operational cycles of dishwasher 10. The detailed construction of treating agent dispensing means 40, beyond its comprising a reservoir 41, is not critical to the present invention and therefore will not be described in detail. In may be constructed -in accordance with U.S. Patent No. 3,198,387, issued Aug. 3, 1965 to Norman L. Kend-t and John A. Dicken, J r. and assigned to the General Electric Company, assignee of the present invention.

In accordance with the present invention, an empty indicator, shown generally at 42, is provided to indicate when reservoir 41 has become empty.` As can be seen from FIGURES 2-5 the indicato-r 42 comprises four major elements: a first tube 43, a gauge 44, a second tube 45, and a generally cylindrical support 46.

As most clearly illustrated in FIGUR'ES 6 and 9, tube 43` extends from communication with the lower portion of reservoir 41 upwardly to a high point H1 and then downwardly to a low point L and then upwardly until it connects to the lower end of gauge 44. Tube 45 extends upwardly to a high point H2 and then briefly downwardly Where its terminal end is open to atmosphere. Tube 43, in the area between high point H1 and the junction with gauge 44, is of sucie-nt volume to contain a suitable amount of indicator fluid. As shown in the schematic representation of FIGURE 6, when reservoir 41 is empty, all of the indicator iiuid is contained within tube 43 with no indicator fluid appearing in gauge 44. When reservoir 41 is filled w-ith liquid, air trapped within tube 43 between reservoir 41 and the indicator huid, exerts a pressure on the indicator fluid forcing it up into gauge 44. This condition is illustrated in FIGURE 2. The position of the fluid shown in FIGURES 4 and 6 is the position obtained when reservoir 41 is empty.

I FIGURE 6, of course, is only a schematic representation of the empty indicator 42. In FIG-URE 6 all of the elements are illustrated in a single plane with FIGURE 6 thereby providing a means to more cle-arly envision the relative heights of the Various points within the indicator 42. FIGURE 9', on the other hand, most clearly illustra-tes the relative positions of the vario-us points within the indicator 42 in all three dimensions. Referring to FIGURES 2-5 and 9, it can be seen that tube 43- extends upwardly from reservoir 41 externally of support 46 until it reaches high point H1 which is at the place where tube 43 passes over a peg 47 projecting from the outer surface of support 46. Tube 43 passes through an opening 48 in support 46 just bey-ond high point H1 and from there tube 43 passes down inside of support 46 to opening 49` in support 46, through which it passes, and then begins a helical path, still downwardly, to low point L. Tube 43 bends upwardly from low point L and connects to the low side of gauge 44.

Gauge 44 is inclined, from the point where it interconnects with tube 43 upwardly to the point where it connects with tube 45, only a small amount sufiicient to assure drainage of the indicator fluid from the gauge 44 when the reservoir 41 becomes empty. Off course, gauge 44 must be constructed from a material which is either transparent or translucent so that one can visibly observe the presence or absence of indicator fluid within the gauge. Gauge 44 is secured to support 46 by arms 50' and 51 which extend out from support 46 and which may be integral with support 46. A shield 52, having a ilange 53 and a gauge receiving portion 54, is carried by arms 50 and S1.

As mentioned above, a second tube 45 is connected to the upper end of gauge 44 and serves primarily to vent the upper end of gauge 44 to atmosphere in such a manner that loss of indicator fluid is virtually impossible even though indicator 42 may be tipped 90 in any direction. Again referring to FIGURES 2-5 and 9, it can be seen that tube 45 extends progressively upwardly from its connection with gauge 44 in a helical fashion about the exterior of support 46 until it reaches a high point H2 from which it extends downwardly, passing through a bracket 5S, and then terminating with its terminal end open to atmosphere.` Bracket 55 may be integrally formed with support 46 and is provided prim-arily to prevent tube 45 from unraveling from support 46.

In the preferred embodiment of the present invention, tubes 43 and 45l are made from a relatively inexpensive plastic which is extremely flexible and convenient to for-m into the required helical configuration. An example of such material would be iiexible vinyl, commercially availlable under the trade name Highly Plasticised Transparent Vinyl Tubing as manufactured by The B. F. Goodrich Company. This particular material, as mentioned above, is especially suitable for use as tubing; however, since this material may discolor from prolonged cont-act with the indicator liu-id, the preferred embodiment of the present invention comprises a glass gauge 44 since glass is substantially inert to the indicator fluid and, of course, is transparent to allow visible observation of the presence or absence of indicato-r fluid in the gauge 44. This arrangement necessitates a connection between the gauge and tubing at each end of the gauge.

Referring to FIGURES 7 and 8, cross sectional detailed views of the aforementioned connections a-re shown. In EIGURE 7 the connection between tube 45 and gauge 44 is shown and includes a hollow rigid insert 56, which may be made from a suitable metal or rigid plastic, within the end portion of tube 45. The insert serves to hold tube 45 in its original shape While a heat shrinltable plastic connector 57 is positioned over the end portion of tube 4S and the end portion of gauge 44.

FIGURE 8 illustrates the connection between gauge 44 and tube 43 which includes a heat shrinkable plastic connector 58 similarto connector 57; however, instead of insert 56 a plug S9 having a small orifice 60 therethrough is provided. Plug 59 serves to retain tube 43 in its original shape in a manner similar to the way the insert 56 maintains tube 45 in its original shape; however, plug 59, due to the small orifice 60, which is equivalent to a restriction in the tube 43, serves the second function of slowing down the rate at which the indicator fluid can flow whenever the indicator 42 is suddenly moved from its normal vertical disposition. Without the orifice, the indicator fluid would flow more rapidly and the rapid flow would tend to create air bubbles within the indicator uid.

The helical configuration of tubes 43 and 45 provide a third dimension for the path along which the indicator fluid must ow as it moves back and forth within indicator 42. For example, if indicator 42 had the physical configuration shown in the schematic diagram in FIG- URE 6, the fluid would follow a path comprising only two dimensions, namely, vertical and horizontal within the plane of the drawing. The helical configuration as shown in FIGURES 2-S, i.e., with the helical portions being co-axial, creates an additional horizontal path for v the indicator fluid. Because the fluid has a three-dimensional path the entire indicator 42 may be rotated 90 in any direction from the position illustrated in FIGURE 2 without loss of the indicator fluid. Additionally, due to the presence of orifice 60, the rate of flow at which the fluid will move upon sudden tipping of the indicator 42 is relatively slow so that bubbles are not created within the fluid.

It has been found in practice that an especially suitable indicator fluid is a highly refined mineral oil which may be dyed to any convenient color. Highly refined mineral oil is especially suitable because it has a relatively low Vapor pressure which allows tube 45 to be opened to atmosphere without measurable loss of fluid over a period of years. Of course, having tube 45 open to atmosphere avoids any barometric action of the indicator. Since both tube 45 and the reservoir 41 are vented to atmosphere, any variations in atmospheric pressure are automatically compensated for.

Thus it can be seen that the present invention provides an effective, commercially feasible reservoir empty indicator wherein the color of the indicator fluid is independent of the color of the liquid in the reservoir and wherein the indicator is capable of being tipped 90 in any direction without affecting its operation once it is returned to its original position.

As will be evident from the foregoing description, certain aspects of the invention are not limited to the particular details of the construction of the example illustrated, and it is contemplated that various other modifications or applications will occur to those skilled in the art. It is therefore intended that the appended claims shall cover such modifications and applications as do not depart from the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An empty indicator for a liquid reservoir comprising:

(a) a gauge having a first end and a second end,

(b) a first tube extending from the lower portion of the reservoir to said first end of said gauge,

(c) a second tube extending upwardly from said second end of said gauge and being open to the atmosphere,

(d) said first tube having a helical portion and said second tube having a helical portion co-axial with said helical portion of said first tube,

(e) said first tube having a high point and said second tube having a high point with said high points being at approximately the same level, and

(f) indicator fluid normally positioned in said first tube when the reservoir is substantially empty,

(g) said indicator fluid being moved into said gauge by pressure created within said first tube when the reservoir is filled with liquid.

2. The indicator defined in claim 1 further comprising a restriction in said first tube to reduce the rate at which said indicator fluid can flow.

3. An empty indicator for a liquid reservoir comprising:

(a) a gauge having a high end and a low end,

(b) a first tube extending from the lower portion of the reservoir to said low end of said gauge,

(c) a second tube extending upwardly from said high end of said gauge and being open to the atmosphere,

(d) said first tube having a helical portion and said second tube having a helical portion co-axial with said helical portion of said first tube,

(e) said first tube having a high point and said second tube having a high point with said high points being at approximately the same level, and

(f) indicator fluid normally positioned in said first tube when the reservoir is substantially empty,

(g) said indicator fluid being moved into said gauge by pressure created within said first tube when the reservoir is filled with liquid.

4. An empty indicator for a liquid reservoir compris- (a) a gauge having a high end and a low end,

(b) a first tube extending from the lower portion of the reservoir to said low end of said gauge,

(c) a second tube extending upwardly from said high end of said gauge and being open to the atmosphere,

(d) a support disposed above the reservoir and adapted to support said first tube and said second tube, and

(e) indicator fluid normally positioned in said first tube when the reservoir is .substantially empty,

(f) said indicator fluid being moved into said gauge by pressure created within said first tube when the reservoir is filled with liquid,

(g) said first tube having a helical portion and said second tube having a helical portion co-axial with said helical portion of said first tube,

(h) said first tube having a high point and said second tube having a high point with said high points being at approximately the same level.

5. The indicator dened in claim 4 further comprising a restriction in said first tube to reduce the rate at which said indicator fluid can flow.

6. The indicator defined in claim 4 wherein said gauge is transparent.

7. An empty indicator for a liquid reservoir comprismg:

(a) a gauge having a high end and a low end,

(b) a first tube extending from the lower portion of the reservoir to said low end of said gauge,

(c) a second tube extending upwardly from said high end of said gauge and being opened to the atmosphere,

(d) a support including a hollow cylinder disposed above the reservoir and adapted to support said first tube and said second tube,

(e) said first tube having a portion passing Within said cylinder, and

(f) indicator fluid normally positioned in said first tube when the reservoir is substantially empty,

(g) said indicator fluid being moved into said gauge lby pressure created within said first tube when the reservoir is filled with liquid,

(h) said first tube and said second tube each having a portion formed in a helix whereby said indicator fluid will not escape from the indicator when the indicator is tipped References Cited by the Examiner UNITED STATES PATENTS 1,646,957 10/ 1927 Eynon 73-299 1,835,995 12/1931 Cheney 73-299 2,744,487 5/1956 Moore et al. 73-323 X 3,209,597 10/1965 Fowler 73-401 LOUIS R. PRINCE, Primary Examiner.

D. M. YASICH, Assistant Examiner. 

1. AN EMPTY INDICATOR FOR A LIQUID RESERVOIR COMPRISING: (A) A GAUGE HAVING A FIRST END AND A SECOND END, (B) A FIRST TUBE EXTENDING FROM THE LOWER PORTION OF THE RESERVOIR TO SAID FIRST END OF SAID GAUGE, (C) A SECOND TUBE EXTENDING UPWARDLY FROM SAID SECOND END OF SAID GAUGE AND BEING OPEN TO THE ATMOSPHERE, (D) SAID FIRST TUBE HAVING A HELICAL PORTION AND SAID SECOND TUBE HAVING A HELICAL PORTION CO-AXIAL WITH SAID HELICAL PORTION OF SAID FIRST TUBE, 